A. Ajami, W. Husinsky, M. Tromayer, P. Gruber, R. Liska, A. Ovsianikov:
"Measurement of degenerate two-photon absorption spectra of a series of developed two-photon initiators using a dispersive white light continuum Z-scan";
Applied Physics Letters, 111 (2017), S. 0719011 - 0719014.

Kurzfassung englisch:
To achieve efficient micro- and nanostructuring based on two-photon polymerization (2PP), the
development and evaluation of specialized two-photon initiators (2PIs) are essential. Hence, a reliable
method to determine the two-photon absorption (2PA) spectra of the synthesized 2PIs used for
2PP structuring is crucial. A technique by which absolute visible-to-near-infrared 2PA spectra of
degenerate nature can be determined via performing a single dispersive white-light continuum
(WLC) Z-scan has been realized. Using a dispersed white light beam containing 8 fs pulses at
wavelengths ranging from 650 nm to 950 nm, the nonlinear transmittance as a function of the sample
position can be measured for all spectral components by performing a single scan along the
laser beam propagation direction. In this work, the 2PA spectrum of three different 2PIs was determined
using this technique. 2PP structuring was also accomplished using the developed 2PIs at different
wavelengths. Tuning the wavelength of the laser to match the peak of the 2PA spectra of the
developed 2PIs resulted in lower intensity thresholds and facilitated higher structuring speeds. As
an example, using M2CMK 2PI for 2PP, the scanning speed can be increased up to 5 folds when
the laser wavelength is tuned to 760 nm (i.e., 2PA maximum) instead of the conventionally used
800 nm.

Elektronische Version der Publikation:

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